Simplify the following expression: $x = \dfrac{1}{4t} + \dfrac{1}{6t}$
Solution: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $4t$ and $6t$ $\lcm(4t, 6t) = 12t$ $ x = \dfrac{3}{3} \cdot \dfrac{1}{4t} + \dfrac{2}{2} \cdot \dfrac{1}{6t} $ $x = \dfrac{3}{12t} + \dfrac{2}{12t}$ $x = \dfrac{3 +2}{12t}$ $x = \dfrac{5}{12t}$